Access to HTTP Headers?

[notdodgy]

I am using a Atom Matrix.
My aim is to query a YouTube Channel to see if it is live or not. The Display on the Atom will used to give a simple status display.
According to the article I found on getting the live stream status, the length of the live header is half the length of the not live header.

My problem is as soon as I try and read the HTTP response with Get Data, it fails, though the response code is 200, which suggests success.

I realise I may be doing something wrong.
It may be the response is too big for the device to process?
The url returns a lot, including video streams, in a normal browser.

Is there a way to just get the returned headers?
Or get the length of the returned data?

Example Code: